EFFECTS OF NOTCHING 173 



notches on single buds, an exhaustive treatment of the sub- 

 ject requires a short notice of the influence which similar 

 notches exert on already existing branches. Bark-notches 

 above or below a branch bearing spurs act in a very slight 

 degree on the branch in question ; a complete girdle around 

 the base of the branch acts, of course, as an ordinary 

 girdle. A quarter girdle on the under side causes the same 

 effect, but in a small degree, for the stopping of the cam- 

 bium fluids is almost completely obviated by the possibility 

 of their moving off to one side. An upper cut out of the 

 bark can also have but the same small influence on the 

 spurs of the branch under experiment, as the cut attains the 

 importance of a quarter girdle to the spurs while the branch 

 itself can in no way be influenced by this bark -notching, 

 because the downward -flowing cambium fluid from the 

 spurs can, of course, be held back, but cannot exert an in- 

 fluence on the branching below the girdle. In practice, 

 therefore, such bark injuries have no importance whatever. 



"It is otherwise with vigorous notches in the wood below 

 or above a branch. By means of these notches the root -sap 

 is either cut off or led to these branches. The more vig- 

 orous the notching on a spur above one of its branches, 

 the more the latter receive of the crude sap, and the leaves 

 are the more stimulated to activity; the leaves become 

 larger, the internodes of greater length, the number of shoots 

 and leaves is increased, and an increased production of 

 wood is the result. Directly opposite is the effect of a notch 

 under a branch or twig. A large portion of the supply 

 destined for the assimilating organs is cut off from the 

 branch, and the diminished production of wood is a natural 

 consequence. The sap hindered in its course is carried to 

 other branches in increased quantities, and particularly to 

 one which may be notched above and therefore already 

 favored, if such should happen to be in the immediate 

 neighborhood of the first. 



" With reference to the technical execution of the notches, 



